反应详情

In a manner analogous to that described in Example 1(D)(c), from 4 g of tert.butyl 2-ethyl-hexahydro-1,3-dioxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate and 5.43 g of S-(2-bromoethyl) thioacetate there was obtained tert.butyl 2-(2-acetylthioethyl)-2-ethyl-hexahydro-1,3-dioxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate as a mixture of diastereomers. Chromatography gave 1.1 g (20%) of diastereomer A having a melting point of 82°-84° C. (from diethyl ether/hexane) and 0.4 g (7%) of diastereomer B in the form of a colorless oil.